Obviously masters has provided the correct answer. Where did you have trouble in this problem? Comparing A, B and C, we see that they differ in statements 2, 4, and 5. "Definition of a midpoint" should have raised a red flag or two, since this given info is about an ANGLE bisector.
"SSS" is terribly wrong because in the preceding statements, three sides were not mentioned.
"AAA" is wrong for the same reason... two angle and a side (the included side) were mentioned, not three angles.

Also, knowing what symmetry and commutative properties look like would immediately rule those out as justification for statement 4.